DESCRIPTION: Piezoelectric quartz crystal microbalance (QCM) is a powerful tool to measure mass accretion on surfaces in the nanogram range. In the past 10 years, it has found more and more applications in a variety of biological studies from protein-protein interaction, DNA hybridization, surface attachment and biofilm formation, to detection of pathogens in food, water, and urine samples. Nevertheless, this powerful technique has not been applied in Dentistry. In this exploratory research application, investigators from UCLA School of Dentistry (UCLA) and Chemical and Environmental Engineering Department of University of California-Riverside (UCR) are partnering to introduce this technology to Dentistry by developing an integrated system combining QCM with fluidic chamber adaptable to laser scanning confocal microscopy (LSCM). We posit that this integrated system will allow for real-time measurement of biomass accretion with simultaneous analysis of structural development during biofilm formation. It will also allow for rapid, sensitive, and specific detection of oral pathogens with simultaneous image confirmation. Two Specific Aims are proposed for this study. Aim 1 is to develop a LSCM compatible, integrated QCM/fluidic chamber system for oral biofilm studies. Aim 2 is to apply QCM for rapid detection and quantification of S. mutans in mixed cultures. The outcome of this study will be the novel development and application of the QCM technology in Dentistry, which will result in acquisition of new knowledge in Dental biofilm research and development of a novel diagnostic tool that has the potential to be developed into a chair side device for oral pathogen detection.